AIA+2030 Session VI

AIA+2030 Session VI Illuminating Savings: Daylighting and Integrated Lighting Strategies

Ramana Koti Building Performance Analyst

Context

Context – Critical Regionalism Excerpt from Critical Regionalism Essay by Kenneth Frampton Character of architecture in a region emerges from the way designers work with building form and the fenestration to deal with light and climate control. It advocates the use of controlled daylight that, for example, causes the exhibition volume in an art gallery to change with time, season and humidity, as opposed to the exclusive use of artificial light.

Context – Lighting’s Share

Lighting’s share of commercial building energy use Source

http://apps1.eere.energy.gov/buildings/publications/pdfs/corporate/rd_breakthroughs.pdf


Lighting’s share of commercial building energy use Source

http://apps1.eere.energy.gov/buildings/publications/pdfs/corporate/rd_breakthroughs.pdf


Annual operating costs per ft² in a typical office space

Context - Relevance Which of the follow ing definitions for daylighting is the m ost relevant to you? Designers (Lighting, Architects, Interior)

Engineers & Energy Consultants

40

20

0

Architectural

Building Energy Consumption

Cost

Lighting Energy Savings

Load Management

Source

Results of a 2006 survey on the role of daylighting in sustainable design by Lawrence Berkeley National Laboratory and National Research Council Canada – 120 Respondents

Context – Circadian Rhythm

Context – Recent Developments Daylighting Forum after the Lightfair 2010 Attended by 90 daylighting experts including researchers, software company representatives, code development committees, professional organizations, manufacturers, practitioners etc. Unprecedented industry-wide interaction. Topics discussed: •Daylight Performance Metrics •Codes and Standards •Human Factors - Visual Comfort, Manual Blinds Usage

Source

Personal Attendance

Context – All Players

Lighting Control Applications • Daylight Dimming • Occupancy Sensors • Time Scheduling • Multi-level Switching • Demand Response (Peak Reduction) • Manual Switching or Dimming • Lumen and Illuminance maintenance

Image Source http://www.daintree.net/lighting/our-system.php?04689c51410dea3ab5cc32b2b01c7ae7=8335738ce4b1fae75900443f3fcb26df

Design

Design – Daylighting Guidelines 1. Don’t overcomplicate the daylighting process 2. Don’t waste money on daylighting features if you don’t control artificial lighting first 3. Position lighting for maximum effectiveness 4. Use tall windows to maximize light penetration 5. Eliminate glazing below sill height

6. Focus on “effective aperture.” 7. Make sure the building program relates to natural daylighting 8. Calculate daylighting depth 9. Address light shelf design 10. Account for climate and geography 11. Use appropriate materials and colors to finish spaces 12. Take into account the payback period of daylighting components 13. Focus on new construction Source

Source: http://www.bdcnetwork.com/article/13-daylighting-guidelines

Important Daylight Metrics

Daylight Factor The ratio of the internal illuminance at a point in a building to the unshaded, external horizontal illuminance under a CIE overcast sky. (CIE is the Commission Internationale de l’Eclairage, which has developed a series of mathematical models of ideal luminous distributions under different sky conditions.)


Daylight Autonomy: For a sensor point, it is the percentage of occupied times of the year when the minimum illuminance requirement at the sensor is met by daylight alone.


Useful Daylight Illuminances Aims to determine when daylight levels are useful for the occupant, in terms of being neither too dark nor too bright (between 100 lux and 2000 lux).


Daylight Saturation Percentage The daylight saturation percentage for 40 foot-candles (DSP40 ) to 400 foot-candles (DSP400) is the percent of hours and the percent of classroom floor area between 8 a.m. and 3 p.m., Monday through Friday, from Aug. 15 through June 15 when daylight provides at least 40 foot-candles or more of illumination at a work plane located 30 inches (76 centimeters) above the floor. Achieving a DSP of 400 is an indicator of over-lighting and glare, and is therefore penalized.

Example Exercise 1 – Daylight Autonomy (DA), Sensor Example Day, one sensor

fc

Hour 1

25

Hour 2

30

Hour 3

36

Hour 4

42

Hour 5

55

Hour 6

32

Hour 7

31

Hour 8

16

If lighting setpoint = 30 fc,

Daylighting Autonomy = ?

Image Source http://www.stanford.edu/group/narratives/classes/08-09/CEE215/ReferenceLibrary/Daylighting/A%20Standard%20Daylight%20Coefficient%20Model%20for%20Dynamic%20Daylighting%20Simulations.pdf

Example Exercise 1 – DA Sensor, Answer Example Day, one sensor

fc

Hour 1

25

Hour 2

30

Hour 3

36

Hour 4

42

Hour 5

55

Hour 6

32

Hour 7

31

Hour 8

16


Daylighting Autonomy = 6 hours/8 hours = 75%


Example Exercise 2 – DAmax, Sensor Example Day, one sensor

fc

Hour 1

25

Hour 2

30

Hour 3

360

Hour 4

42

Hour 5

55

Hour 6

32

Hour 7

31

Hour 8

16


DAmax= ?


Example Exercise 2 – DAmax Sensor Answer Example Day, one sensor

fc

Hour 1

25

Hour 2

30

Hour 3

360

Hour 4

42

Hour 5

55

Hour 6

32

Hour 7

31

Hour 8

16


DAmax = 1 hours/8 hours = 12.5% (limit DAmax to 5% for the entire year) Image Source http://www.stanford.edu/group/narratives/classes/08-09/CEE215/ReferenceLibrary/Daylighting/A%20Standard%20Daylight%20Coefficient%20Model%20for%20Dynamic%20Daylighting%20Simulations.pdf

Example Exercise 3 – DA, Space

DA55

DA60

DA55

DA50

DA65

DA75

DA70

DA60

% Space with DA50 and above = ? % Space with DA60 and above = ? % Space with DA70 and above = ?


Example Exercise 3 – DA Space, Solution

DA55

DA60

DA55

DA50

DA65

DA75

DA70

DA60

% Space with DA50 and above = 8/8 = 100% % Space with DA60 and above = 5/8 = 62.5% % Space with DA70 and above = 2/8 = 20%


Metrics and Daylighting Design Daylighting Design

DA%

Excellent

80 to 100

Good

60 to 80

Adequate

40 to 60

Data Source

http://www.archenergy.com/SPOT/SPOT_Daylight%20Autonomy%20Report.pdf

Implementation

Types of Photosensors

Image Source http://eetdnews.lbl.gov/nl20/eetd-nl20-4-daylighting.html http://www.smgov.net/Departments/OSE/categories/content.aspx?id=4682

Types of Photosensors

Free-standing

Image Source http://algonline.org/docs/index.php?photosensor-controls-commissioning

Luminaire-integrated

Light Output Vs. Energy Savings

At 20% dim level, the energy savings is approximately 60% compared to operating the lamp at full power. Ballasts that dim lamps down to less than 5% light output have a maximum energy savings of about 80% compared to full light output operation. Image Source http://www.lrc.rpi.edu/programs/NLPIP/tutorials/photosensors/energy.asp

Daylighting Controls - Commissioning • Most successful when performed after the furniture and occupants have moved in • A large percentage of daylighting first cost • Adjustments to photosensor parameters • photosensor location • view direction • field of view • Adjustments to algorithm parameters • On/Off • Down/Up • Target Setpoints & related time delays Source http://algonline.org/docs/index.php?photosensor-controls-commissioning

Codes and Standards

What Guidance do Codes and Standards Provide? •

Conditions that trigger skylight requirement

•

What minimum fraction of total square footage shall be skylit?

•

What constitutes an acceptable skylight?

•

Conditions that trigger automated daylighting

controls requirement •

What constitutes acceptable automated daylighting controls?

•

Depth/extent of daylit zone in sidelit and toplit conditions, calculations involved (how much electric lighting to control?)

•

What conditions are exceptions to mandatory

requirements? •

How to demonstrate compliance with daylighting requirements?

California Title 24 Energy Code – Skylight Area Requirement

California Title 24 Energy Code – Mandatory Requirements

California Title 24 Energy Code – Sidelighting

California Title 24 Energy Code – Toplighting

ASHRAE/IESNA 90.1-2010: Daylighting Requirements ASHRAE/IESNA 90.1-2010 was released last year and contains provisions pertaining to automatic daylight controls in certain spaces.

Section 9.4.1.4 addresses sidelit areas. Sidelit areas (as defined in the codes definition section) greater than or equal to 250 ft2 are required to have multilevel photocontrol. The photocontrol needs to have at least one step between 50 percent and 70 percent of design power and one step below 35 percent. A significant exception is made for retail spaces, among others. Section 9.4.1.5 addresses toplit areas. Toplit areas (as defined in the codes definition section) greater than or equal to 900 ft2 are required to have multilevel photocontrol. The photocontrol needs to have at least one step between 50 percent and 70 percent of design power and one step below 35 percent. A significant exception, among others, is made for buildings in Climate Zone 8 with total toplit areas below 1,500 ft2.

Source: http://www.ecw.org/email/dlc-enews-jan2011-web.html

ASHRAE/IESNA 90.1-2010: Daylighting Requirements c) Section View with obstructions

Head Height (HH)

Vertical Obstruction > 5 feet

1 x (HH)

Primary Sidelighted Area

Secondary Sidelighted Area

d) Plan View with obstructions 1 x (HH)

1 x (HH)

2 ft Vertical Obstruction > 5 feet

Primary Sidelighted Area 2 ft

Primary Sidelighted Area




ASHRAE/IESNA 90.1-2010: Daylighting Requirements


ASHRAE/IESNA 90.1-2010: Daylighting Requirements


Other Codes Code

Daylighting Mandatory?

Comments

Oregon State Code

No

Where daylighting provided, controls mandatory

Washington State Code

No

Where daylighting provided, controls mandatory

IECC

No

Except when choosing the Total Performance Paths for Warehouses

ASHRAE/USGBC/IESNA 189.1

Yes

Somewhat similar to Title 24 and ASHRAE 90.1

International Green Construction Code (IGCC)

Yes

Prescriptive, has a unique calculation method based on ‘Total Daylight Potential’


Resources

Daylighting, Architecture and Lighting Design

Advanced Lighting Guidelines

Commercial Lighting Solutions (DOE)






DEMO - www.lightingsolutions.energy.gov/

Hands-on Exercise (See Handout)

Hands-on Exercise Senso r#

Classroom cross-section

Sensor locations for simulation

DF [%]

DA [%]

DA

DA

UDI

UDI

UDI

con

max

200

[%]

[%]

[%]

[%]

[%]

DSP [%]

1

2

89

94

5

4

87

10

83

2

3.5

92

95

15

3

64

33

57

3

4.4

93

96

19

3

49

48

43

4

4.1

91

95

13

3

58

39

57

5

2.1

87

93

8

4

84

13

72

6

2.6

88

94

4

4

87

10

81

7

3.1

89

94

8

4

74

22

72

8

2.9

87

93

0

4

81

15

97

9

2.3

85

93

0

4

92

4

97

10

2.8

86

93

3

4

89

7

86

11

2.8

85

93

4

4

88

8

85

12

2.8

84

92

4

4

88

8

84

13

2.1

81

91

2

4

91

4

87

14

2.4

82

92

2

4

92

3

87

15

2.7

84

92

2

4

92

4

87

16

2.3

82

91

0

5

95

0

95

17

1.3

74

88

3

5

89

6

84

18

1.4

76

88

0

5

95

0

92

19

1.5

76

89

0

6

94

0

92

20

1.5

76

88

0

6

94

0

91

Simulation results

Hands-on Exercise Assuming the 20 sensors are representative of the entire classroom area: % of classroom space with Daylight Factor (DF) ≥ 2% % of classroom space with Daylight Autonomy (DA) ≥ 80% % of classroom space with DAmax ≤ 5%

Based on the Collaborative for High Performance Schools (CHPS) Daylighting Criteria in the table below, how many points would the Classroom space earn?